cpu.c

// Copyright (c) 2010 Joseph D Poirier
// Distributable under the terms of The New BSD License
// that can be found in the LICENSE file.

#ifdef _WIN32
# define WIN32_LEAN_AND_MEAN
# include <windows.h>
#elif defined(__linux__) || defined(__APPLE__) || defined(__FreeBSD__)
# include <stdlib.h>
# include <sys/param.h>
# include <sys/sysctl.h>
# include <unistd.h>
# ifndef _SC_NPROCESSORS_ONLN
#  define _SC_NPROCESSORS_ONLN (-1)
# endif
# ifndef _SC_NPROCESSORS_CONF
#  define _SC_NPROCESSORS_CONF (-1)
# endif
#else
# error "Invalid GOOS: must be darwin, freebsd, linux, or windows"
#endif

#include "cpu.h"

#ifdef __APPLE__
# define MIB_0   CTL_HW
# define MIB_1   HW_AVAILCPU
#elif defined(__linux__) || defined(__FreeBSD__)
# if defined(CTL_HW) && defined(HW_NCPU)
#  define MIB_0   CTL_HW
#  define MIB_1   HW_NCPU
# endif
#endif


bool have_cpuid(void) {
    uint32_t a = true;
#ifdef __i386__
    __asm__ __volatile__ (
        "pushfl\n\t"
        "popl %%eax\n\t"
        "movl %%eax, %%ecx\n\t"
        "xorl $0x200000, %%eax\n\t"
        "pushl %%eax\n\t"
        "popfl\n\t"
        "pushfl\n\t"
        "popl %%eax\n\t"
        "xorl %%ecx, %%eax\n\t"
        "shrl $21, %%eax\n\t"
        "andl $1, %%eax\n\t"
        "movl %%eax, %0\n\t"
        : "=r"(a)
        :
        : "eax", "ecx"
    );
#endif
    return a;
}

void cpuid(regs_t* r, uint32_t f1, uint32_t f2) {
    __asm__ __volatile__ (
#ifdef __i386__
        "push %%ebx; push %%edx;"
#endif
#ifdef __amd64
        "push %%rbx; push %%rdx;"
#endif
        "cpuid;"
        "movl %%eax, 0(%2);"
        "movl %%ebx, 4(%2);"
        "movl %%ecx, 8(%2);"
        "movl %%edx, 12(%2);"
#ifdef __i386__
        "pop %%edx; pop %%ebx;"
#endif
#ifdef __amd64
        "pop %%rdx; pop %%rbx;"
#endif
        : "=a"(f1), "=c"(f2)
        : "D"(r), "a"(f1), "c"(f2)
        : "memory"
    );
}

uint32_t onlineProcs(void) {
#ifdef _WIN32
    return (uint32_t) confProcs();
#else
    int x; uint32_t cnt; size_t sz = sizeof(cnt);
# if defined(MIB_0) && defined(MIB_1)
    int mib[2] = {MIB_0, MIB_1};
# endif
    if ((x = sysconf(_SC_NPROCESSORS_ONLN)) != -1) {
        return (uint32_t) x;
    }
# if defined(MIB_0) && defined(MIB_1)
    if ((x = sysctl(mib, 2, &cnt, &sz, NULL, 0)) != -1 ) {
        return (uint32_t) x;
    }
# endif
# ifndef __linux__
    if ((x = sysctlbyname("hw.ncpu", &cnt, &sz, NULL, 0)) != -1 ) {
        return (uint32_t) x;
    }
# endif
# if defined(MIB_0) && defined(MIB_1)
    if ((x = sysctlnametomib("hw.ncpu", mib, &sz)) != -1 ) {
        return (uint32_t) x;
    }
# endif
    return 0;
#endif
}

//  Number of OS configured processors
uint32_t confProcs(void) {
#ifdef _WIN32
    SYSTEM_INFO sysinfo;
    GetSystemInfo(&sysinfo);
    return (uint32_t) sysinfo.dwNumberOfProcessors;
#else
    int x;
    if ((x = sysconf(_SC_NPROCESSORS_CONF)) == -1) {
        x = onlineProcs();
    }
    return (uint32_t) x;
#endif
}